1. Field of the Invention
This invention relates to a vehicle safety air bag apparatus and, more particularly, to an air bag apparatus for protecting a passenger seated in a front seat against injuries during front-end collisions.
2. Description of Related Art
For protecting a passenger seated in a front seat against injuries during a collision, a safety air bag apparatus is typically installed behind a dashboard in front of the passenger seat of the vehicle. An air bag apparatus of this kind has an air bag case, containing a folded air bag and an inflator or gas generator, which is closed by an air bag lid capable of opening upwards. The inflator generates a pressurized inert gas, and inflates and expands the folded air bag. During inflation and expansion of the air bag, the air bag applies pressure to the air bag lid so as to open it. This allows the air bag to expand in the vehicle interior or compartment so as to act as a cushion on the occupant of the front passenger seat.
Such a safety air bag apparatus is installed so as to provide a sufficient distance, or a sufficient space, between the air bag container and the occupant of the front passenger seat in order to prevent the occupant from being hit by an air bag lid during inflation and expansion of the air bag. This is particularly important if the occupant is a child standing close to the instrument panel of the vehicle. Also, the distance or space is important in order to assure that the occupant seated in the front passenger seat is contacted by the air bag after complete inflation of the air bag. When providing such a sufficient space between the air bag container and the occupant, the instrument panel structure is typically formed with a shelf which extends from an outer surface of an instrument panel toward the air bag container in a space inside the instrument panel structure.
For a desirable and aesthetically pleasing instrument panel structure appearance, the air bag lid is preferably flush with the instrument panel and has an outer surface with a profile matching the outer profile of the instrument panel. However, since the instrument panel inclines backwards and down relative to a direction in which the air bag expands, the expanding air bag first contacts an upper portion of the air bag lid, above the center of gravity of the air bag lid, if the air bag is hinged so as to open upwards. The typical air bag lid is thus unable to open lightly and smoothly, and opens somewhat sluggishly.